Gufw - Gufw is an easy, intuitive way to manage your Linux firewall.

Symantec Email Security.cloud - Symantec Email Security.cloud provides always-on, inbound and outbound email security against malware, targeted attacks, and advanced threats

Little Snitch - Little Snitch is a firewall application that monitors and controls outbound internet traffic.

pfSense - pfSense is a free and open source firewall and router that also features unified threat management, load balancing, multi WAN, and more

netfilter - Netfilter software comprises iptables, ipset, conntrack-tools, libnetfilter and more.

SonicWall - SonicWall security solutions protects your network, systems, users and data from cyber threats.